The light provided, for example, by an ultra-high-pressure (UHP) lamp or other high intensity discharge lamp in a digital projection system does not contain enough red light to balance the green light and blue light produced by the lamp.
A dichroic beam splitter may be used to combine light from a UHP lamp and red light from an additional light source to produce a combined output beam. The beam splitter excludes from the output beam the portion of light from the UHP lamp that is in the same spectral band as the red light from the additional source.